Surface modification of polymer films with low-energy electron beam (8.5 keV)

The physical and mechanical properties and structure of polyimide (PI), polyethylene terephthalate (PET) and polytetrafluoroethylene (PTFE) polymer films treated with electron beam with the energy of 8.5 keV have been investigated. It is shown that the optical characteristics of the films change depending on the electron fluence, and the degree of manifestation of the observed effects (5–8% decrease of light transmittance of PTFE films and increase of light transmittance of PI and PET films) depends on this parameter. It has been discovered that the reason for changes in the optical properties of polymer films is the occurrence of defects in the structure of samples, primarily associated with thermal degradation processes. It is also shown that with the help of low-energy electron beam it is possible to change the surface free energy, the increase of the polar part of which is connected with the increase of the number of polar groupings near the surface.